Field
The present disclosure relates generally to semiconductor devices with an edge assurance structure.
Background Art
Integrated circuits (“ICs”) are usually produced in large numbers on a semiconductor wafer made of silicon or other semiconductor materials. The wafer is then diced into individual die for assembly into larger circuits or systems.
Die edge delamination or cracking can result in reliability problems and yield loss, and therefore is a significant concern in the semiconductor industry. Die edge delamination or cracking can occur during the dicing of the wafer, and has been exacerbated by the introduction of ICs with low-k dielectrics in 65 nm technology node, and beyond. The use of a low-k dielectric reduces the interconnect coupling capacitance, but also reduces mechanical strength and adhesion. Die edge delamination and cracking become even more severe when using laser grooving in the dicing process, where edge chipping can be reduced at the cost of increased thermal damage to the die edges. For example, using laser to cut the wafer at high temperatures can cause metal to oxide. The metal oxidization can enlarge the volume of metal, for example, at the edges of the die. This enlarged metal oxidized layer is not strong enough and can peal or crack. The crack can further enter into the chip and cause function failure.
One way to solve this problem is to develop methods to avoid metal reside after laser grooving. But it has been difficult to develop method to clear all the metal from the wafer and between the chips. Another option is to inspect the dies and screen out the dies with delamination or cracking. Conventionally die edge delamination or cracking is screened by visual inspection and/or time-consuming and inefficient manual probing. This conventional screening method is performed on a low percentage of samples.
The present disclosure will now be described with reference to the accompanying drawings. In the drawings, generally, like reference numbers indicate identical or functionally similar elements. Additionally, generally, the left-most digit(s) of a reference number identifies the drawing in which the reference number first appears.